Extruded seal

Abstract

A filter element, including a filter medium, on which a seal is situated indirectly or directly, which is used for separating the filter intake side from the filter discharge side. The filter medium comprises a fibrous material. The seal is applied indirectly or directly to the filter medium in the extrusion method (FIG. 1).

Description

[0001]The present invention relates to a filter element comprising a filter medium with a seal situated thereon and a method for producing such filter elements.BACKGROUND OF THE INVENTION[0002]In the automobile industry in particular, filter elements are used for the intake air of the internal combustion engine and / or for filtering the air supplied to the interior. Such filter elements have PUR polyester or PUR polyether foam seals for the seal between the unfiltered air side and the filtered air side. One disadvantage of such foam seals is that these seals may absorb moisture and deposits may form on the seals. Furthermore, such glued-on seals may be sheared off during installation into the complex filter housing provided for this purpose and thus no longer fulfill the required sealing tasks.[0003]A filter element is known from DE-OS 26 20 148, for example, which is constructed from corrugated paper filter webs and is enclosed on its lateral front faces using lateral strips, which ...

AI Technical Summary

Benefits of technology

[0007]An advantage of the present invention is that the seal element according to the present invention comprises a polymer material, which produces a very close bond to the fibrous filter medium. Due to the high temperatures of approximately 200° C. which exist at the die during an extrusion method, the seal material penetrates into the fiber scrim of the filter medium and / or partially encloses these fibers, so that the seal material bonds to the fibers in a formfitting way. This produces not only a high strength, but rather also a high sealing effect simultaneously. A further advantage of the present invention is also that the use of the extrusion method results in a shortening of the production time, and thus simultaneously an improvement of the cost-effectiveness of the filter element manufacturing. Where until now, for example, a polyurethane resin (PUR) foam was introduced into a casting mold and had to cure and / or foam up for a certain time, the extrusion method results in the filter element being able to be processed further directly after the extrusion procedure. The seal has outstanding rubber-elastic properties, and simultaneously also has a stabilizing effect on the filter medium.

[0008]According to one embodiment of the present invention, in the event of an indirect connection between filter medium and seal, the possibility exists of providing a medium, such as a nonwoven strip, which is bonded to the filter medium by gluing, welding, or embossing. This medium may fulfill various additional tasks, thus, it is possible with a filter folded in a zigzag shape to cover the front faces of the folds using the medium, the possibility also exists of equipping the medium itself with sealing functions through appropriate implementation, such as crease folding.

[0009]In an advantageous embodiment, an adhesive force of the seal which withstands a tensile load >1 N / mm2 results due to the extrusion method. This seal may comprise a foamed or foaming material.

[0010]For example, it may be a thermoplastic vulcanizate, elastomer, duroplastic, or polyurethane, and / or silicone.

[0011]According to a refinement, the intermediate layer on which the seal is situated is a thermoplastic. To improve the frictional connection, the surface of this plastic may be pretreated, roughened, or textured.

[0012]In a further advantageous embodiment, the seal is implemented from various materials or material components, and / or from multiple layers. Thus, for example, the possibility exists of working with multiple extrusion heads to apply different materials and multiple layers simultaneously. The possibility also exists of extruding multiple layers of seal material on the filter element in sequence or simultaneously in the coextrusion method using a single extrusion head.

Problems solved by technology

One disadvantage of such foam seals is that these seals may absorb moisture and deposits may form on the seals.

Furthermore, such glued-on seals may be sheared off during installation into the complex filter housing provided for this purpose and thus no longer fulfill the required sealing tasks.

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